Commit 589a2004 authored by Maxime Ripard's avatar Maxime Ripard Committed by Stephen Boyd
Browse files

clk: tests: Add tests for notifiers 



We're recently encountered a regression due to the rates reported
through the clk_notifier_data being off when changing parents.

Let's add a test suite and a test to make sure that we do get notified
and with the proper rates.

Suggested-by: default avatarStephen Boyd <sboyd@kernel.org>
Signed-off-by: default avatarMaxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221010-rpi-clk-fixes-again-v1-2-d87ba82ac404@cerno.tech


Tested-by: default avatarMarek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent 096f2a0c

drivers/clk/clk_test.c

+156 −0
Original line number Diff line number Diff line
@@ -2239,10 +2239,166 @@ static struct kunit_suite clk_leaf_mux_set_rate_parent_test_suite = { 
	.test_cases = clk_leaf_mux_set_rate_parent_test_cases,

};



struct clk_mux_notifier_rate_change {

	bool done;

	unsigned long old_rate;

	unsigned long new_rate;

	wait_queue_head_t wq;

};



struct clk_mux_notifier_ctx {

	struct clk_multiple_parent_ctx mux_ctx;

	struct clk *clk;

	struct notifier_block clk_nb;

	struct clk_mux_notifier_rate_change pre_rate_change;

	struct clk_mux_notifier_rate_change post_rate_change;

};



#define NOTIFIER_TIMEOUT_MS 100



static int clk_mux_notifier_callback(struct notifier_block *nb,

				     unsigned long action, void *data)

{

	struct clk_notifier_data *clk_data = data;

	struct clk_mux_notifier_ctx *ctx = container_of(nb,

							struct clk_mux_notifier_ctx,

							clk_nb);



	if (action & PRE_RATE_CHANGE) {

		ctx->pre_rate_change.old_rate = clk_data->old_rate;

		ctx->pre_rate_change.new_rate = clk_data->new_rate;

		ctx->pre_rate_change.done = true;

		wake_up_interruptible(&ctx->pre_rate_change.wq);

	}



	if (action & POST_RATE_CHANGE) {

		ctx->post_rate_change.old_rate = clk_data->old_rate;

		ctx->post_rate_change.new_rate = clk_data->new_rate;

		ctx->post_rate_change.done = true;

		wake_up_interruptible(&ctx->post_rate_change.wq);

	}



	return 0;

}



static int clk_mux_notifier_test_init(struct kunit *test)

{

	struct clk_mux_notifier_ctx *ctx;

	const char *top_parents[2] = { "parent-0", "parent-1" };

	int ret;



	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);

	if (!ctx)

		return -ENOMEM;

	test->priv = ctx;

	ctx->clk_nb.notifier_call = clk_mux_notifier_callback;

	init_waitqueue_head(&ctx->pre_rate_change.wq);

	init_waitqueue_head(&ctx->post_rate_change.wq);



	ctx->mux_ctx.parents_ctx[0].hw.init = CLK_HW_INIT_NO_PARENT("parent-0",

								    &clk_dummy_rate_ops,

								    0);

	ctx->mux_ctx.parents_ctx[0].rate = DUMMY_CLOCK_RATE_1;

	ret = clk_hw_register(NULL, &ctx->mux_ctx.parents_ctx[0].hw);

	if (ret)

		return ret;



	ctx->mux_ctx.parents_ctx[1].hw.init = CLK_HW_INIT_NO_PARENT("parent-1",

								    &clk_dummy_rate_ops,

								    0);

	ctx->mux_ctx.parents_ctx[1].rate = DUMMY_CLOCK_RATE_2;

	ret = clk_hw_register(NULL, &ctx->mux_ctx.parents_ctx[1].hw);

	if (ret)

		return ret;



	ctx->mux_ctx.current_parent = 0;

	ctx->mux_ctx.hw.init = CLK_HW_INIT_PARENTS("test-mux", top_parents,

						   &clk_multiple_parents_mux_ops,

						   0);

	ret = clk_hw_register(NULL, &ctx->mux_ctx.hw);

	if (ret)

		return ret;



	ctx->clk = clk_hw_get_clk(&ctx->mux_ctx.hw, NULL);

	ret = clk_notifier_register(ctx->clk, &ctx->clk_nb);

	if (ret)

		return ret;



	return 0;

}



static void clk_mux_notifier_test_exit(struct kunit *test)

{

	struct clk_mux_notifier_ctx *ctx = test->priv;

	struct clk *clk = ctx->clk;



	clk_notifier_unregister(clk, &ctx->clk_nb);

	clk_put(clk);



	clk_hw_unregister(&ctx->mux_ctx.hw);

	clk_hw_unregister(&ctx->mux_ctx.parents_ctx[0].hw);

	clk_hw_unregister(&ctx->mux_ctx.parents_ctx[1].hw);

}



/*

 * Test that if the we have a notifier registered on a mux, the core

 * will notify us when we switch to another parent, and with the proper

 * old and new rates.

 */

static void clk_mux_notifier_set_parent_test(struct kunit *test)

{

	struct clk_mux_notifier_ctx *ctx = test->priv;

	struct clk_hw *hw = &ctx->mux_ctx.hw;

	struct clk *clk = clk_hw_get_clk(hw, NULL);

	struct clk *new_parent = clk_hw_get_clk(&ctx->mux_ctx.parents_ctx[1].hw, NULL);

	int ret;



	ret = clk_set_parent(clk, new_parent);

	KUNIT_ASSERT_EQ(test, ret, 0);



	ret = wait_event_interruptible_timeout(ctx->pre_rate_change.wq,

					       ctx->pre_rate_change.done,

					       msecs_to_jiffies(NOTIFIER_TIMEOUT_MS));

	KUNIT_ASSERT_GT(test, ret, 0);



	KUNIT_EXPECT_EQ(test, ctx->pre_rate_change.old_rate, DUMMY_CLOCK_RATE_1);

	KUNIT_EXPECT_EQ(test, ctx->pre_rate_change.new_rate, DUMMY_CLOCK_RATE_2);



	ret = wait_event_interruptible_timeout(ctx->post_rate_change.wq,

					       ctx->post_rate_change.done,

					       msecs_to_jiffies(NOTIFIER_TIMEOUT_MS));

	KUNIT_ASSERT_GT(test, ret, 0);



	KUNIT_EXPECT_EQ(test, ctx->post_rate_change.old_rate, DUMMY_CLOCK_RATE_1);

	KUNIT_EXPECT_EQ(test, ctx->post_rate_change.new_rate, DUMMY_CLOCK_RATE_2);



	clk_put(new_parent);

	clk_put(clk);

}



static struct kunit_case clk_mux_notifier_test_cases[] = {

	KUNIT_CASE(clk_mux_notifier_set_parent_test),

	{}

};



/*

 * Test suite for a mux with multiple parents, and a notifier registered

 * on the mux.

 *

 * These tests exercise the behaviour of notifiers.

 */

static struct kunit_suite clk_mux_notifier_test_suite = {

	.name = "clk-mux-notifier",

	.init = clk_mux_notifier_test_init,

	.exit = clk_mux_notifier_test_exit,

	.test_cases = clk_mux_notifier_test_cases,

};



kunit_test_suites(

	&clk_leaf_mux_set_rate_parent_test_suite,

	&clk_test_suite,

	&clk_multiple_parents_mux_test_suite,

	&clk_mux_notifier_test_suite,

	&clk_orphan_transparent_multiple_parent_mux_test_suite,

	&clk_orphan_transparent_single_parent_test_suite,

	&clk_orphan_two_level_root_last_test_suite,